CN111512183B

CN111512183B - System and method for adaptive range coverage using LIDAR

Info

Publication number: CN111512183B
Application number: CN201880083098.8A
Authority: CN
Inventors: M.A.尚德
Original assignee: Waymo LLC
Current assignee: Waymo LLC
Priority date: 2017-12-22
Filing date: 2018-10-31
Publication date: 2023-12-12
Anticipated expiration: 2038-10-31
Also published as: IL275439B1; EP3707531A1; JP2021507207A; IL275439B2; CN111512183A; WO2019125607A1; JP7008139B2; KR20200090271A; EP3707531B1; EP3707531A4; US11340339B2; US20240061089A1; US20190195990A1; US11841464B2; SG11202005134UA; US20220236377A1; IL275439A

Abstract

The present disclosure relates to systems and methods that facilitate light detection and ranging operations. An example method includes determining a light pulse arrangement for at least one light emitter device of a plurality of light emitter devices. The plurality of light emitter devices are operable to emit light along a plurality of emission vectors. The light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of the external environment. The light pulse arrangement comprises at least one light pulse parameter and a listening window duration. The method further comprises causing at least one of the plurality of light emitter devices to emit light pulses according to the light pulse arrangement. The light pulses interact with the external environment.

Description

System and method for adaptive range coverage using LIDAR

Cross Reference to Related Applications

The present application claims the benefit of U.S. patent application Ser. No. 15/852,788, filed on publication No. 12/22, 2017, the disclosure of which is incorporated herein by reference.

Background

Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this section and are not admitted to be prior art by inclusion in this section.

The vehicle may be configured to operate in an autonomous mode in which the vehicle navigates through an environment with little, or no input from the driver. Such autonomous or semi-autonomous vehicles may include one or more sensors configured to detect information about the environment in which the vehicle is operating.

One such sensor is a light detection and ranging (light detection and ranging, LIDAR) device. LIDAR may estimate distances to environmental features as a scene is scanned to assemble a "point cloud" indicative of reflective surfaces in the environment. Each point in the point cloud may be determined by sending a laser pulse and detecting a return pulse (if any) reflected from an object in the environment, and determining a distance to the object based on a time delay between the sent pulse and receiving the reflected pulse. The laser or set of lasers may be scanned rapidly and repeatedly throughout the scene to provide continuous real-time information about the distance to the reflective object in the scene. Combining the measured distance and the orientation of the laser(s) while measuring each distance allows a three-dimensional position to be associated with each return pulse. In this way, a three-dimensional map of points indicating the locations of reflective features in the environment can be generated for the entire scan area.

Disclosure of Invention

The present disclosure relates generally to light detection and ranging (LIDAR) systems, which may be configured to obtain information about an environment. Such LIDAR devices may be implemented in vehicles such as autonomous and semi-autonomous automobiles, trucks, motorcycles, and other types of vehicles that are capable of moving within their respective environments.

In a first aspect, a system is provided. The system includes a plurality of light emitter devices. The plurality of light emitter devices are operable to emit light along a plurality of emission vectors such that the emitted light interacts with an external environment of the system. The system further includes a receiver subsystem configured to provide information indicative of an interaction between the emitted light and an external environment. The system also includes a controller operable to perform operations. The operations include determining a light pulse arrangement (schedule) for at least one light emitter device of the plurality of light emitter devices. The light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of the external environment. The light pulse arrangement comprises at least one light pulse parameter and a listening window duration. The system further comprises causing at least one of the plurality of light emitter devices to emit light pulses according to the light pulse arrangement.

In a second aspect, a method is provided. The method includes determining a light pulse arrangement for at least one light emitter device of the plurality of light emitter devices. The plurality of light emitter devices are operable to emit light along a plurality of emission vectors. The light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of the external environment. The light pulse arrangement comprises at least one light pulse parameter and a listening window duration. The method further comprises causing at least one of the plurality of light emitter devices to emit light pulses according to the light pulse arrangement. The light pulses interact with the external environment.

In a third aspect, a system is provided. The system includes a plurality of light emitter devices. The plurality of light emitter devices are operable to emit light along a plurality of emission vectors such that the emitted light interacts with an external environment of the system. The system further includes a receiver subsystem configured to provide information indicative of an interaction between the emitted light and an external environment. The system also includes a controller operable to perform operations. The operations include determining a light pulse arrangement for at least one light emitter device of the plurality of light emitter devices. The light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of the external environment. The determined light pulse schedule includes at least one light pulse parameter and a listening window duration. The operations further comprise causing at least one of the plurality of light emitter devices to emit a first light pulse according to the determined light pulse arrangement and a second light pulse according to a default light pulse arrangement.

Other aspects, embodiments, and implementations will be apparent to those of ordinary skill in the art from a reading of the following detailed description, with reference to the accompanying drawings where appropriate.

Drawings

FIG. 1A illustrates a sensing system according to an example embodiment.

FIG. 1B illustrates a system according to an example embodiment.

Fig. 2 shows several timing sequences according to an example embodiment.

Fig. 3 shows a carrier according to an example embodiment.

Fig. 4A illustrates a sensing scenario according to an example embodiment.

Fig. 4B illustrates a sensing scenario according to an example embodiment.

Fig. 4C illustrates a sensing scenario according to an example embodiment.

Fig. 4D illustrates a sensing scenario according to an example embodiment.

Fig. 4E illustrates a sensing scenario according to an example embodiment.

Fig. 4F illustrates a sensing scenario according to an example embodiment.

Fig. 5 shows a system with a light emitter device according to an example embodiment.

Fig. 6 shows a method according to an example embodiment.

Detailed Description

Example methods, apparatus, and systems are described herein. It should be understood that the words "example" and "exemplary" are used herein to mean "serving as an example, instance, or illustration. Any embodiment or feature described herein as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or features. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented herein.

Accordingly, the example embodiments described herein are not meant to be limiting. As generally described herein and shown in the figures, aspects of the present disclosure may be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are contemplated herein.

Furthermore, unless the context implies otherwise, the features shown in each figure may be used in combination with each other. Accordingly, the drawings should generally be viewed as constituent aspects of one or more general embodiments, with the understanding that not all illustrated features are necessary for every embodiment.

I. Overview

The LIDAR system may include a transmit assembly (transmit assembly) that includes a plurality of light emitters. In some embodiments, the plurality of light emitters may be arranged along a substrate having a major plane. Further, each light emitter may be arranged to have a different emission angle, such that the plurality of light emitters may be configured to emit light along the main plane at various emission angles (e.g., assuming a 2 meter LIDAR height and flat ground surface and vehicle attitude conditions, in an angular range between +2 degrees above the horizon and-18 degrees below the horizon). The LIDAR system may be configured to rotate about a yaw axis such that the sending assembly and the plurality of light emitters illuminate an environment. In some embodiments, the LIDAR system may rotate at 10Hz or 20 Hz. Other rotation rates are also possible and contemplated herein. In some embodiments, the LIDAR system may provide point cloud information for an autonomous or semi-autonomous vehicle (e.g., a self-propelled car, truck, boat, or aircraft).

In some embodiments, each of the plurality of light emitters may emit light pulses in sequence (e.g., starting by starting the light emitter having the highest emission angle and ending by starting the light emitter having the lowest emission angle, and vice versa). After each light pulse is emitted, there may be a pause (e.g., a "listening" period) during which the light pulse may travel from the light emitter, interact with objects in the environment (e.g., scatter or reflect), and a portion of the light pulse may return to the LIDAR device and be received by the photodetector of the receiving assembly. In some cases, the listening period or listening window where the light pulse travels 150 meters and returns (a total distance of 300 meters) may be about 1 microsecond.

In order to increase the resolution of the yaw angle, the listening window may be reduced for the light pulses emitted by the downwardly directed light emitters. That is, if the light pulse from the downwardly directed light emitter may interact with a ground surface within, for example, 20 meters, the listening window may be reduced to about 130 nanoseconds based on the round trip time of the emitted light pulse. In other embodiments, the range of the listening window may be adjustable between 100 nanoseconds and 2 microseconds; however, other listening windows are also possible. The listening window corresponding to each light pulse may be adjusted based on the possible range to the ground surface in the environment. Thus, the total time to fire each of the plurality of light emitters is reduced, and the LIDAR device may be able to begin a new vertical scan while rotating a smaller yaw angle. In other words, by reducing the total cycle time, at least some of the light emitters may be configured to emit more frequently, and in some embodiments, the LIDAR system may provide finer yaw resolution.

The systems and methods described herein include dynamically adjusting a listening window based on an emission angle of each light pulse and a maximum predicted distance of each yaw angle. That is, as the LIDAR device rotates about the yaw axis, the listening window may be adjusted based on how far the light pulses are expected to travel before they interact with the environment (e.g., ground). The maximum predicted distance may be based on the pose of the LIDAR system and/or a vehicle associated with the LIDAR system (e.g., the pose of the vehicle), and/or may be based on elevation data, which may be obtained from mapping data or sampling data. In an example embodiment, sampling data may include obtaining elevation data by performing a 360 degree scan of the LIDAR system while pulsing the transmitter device with a predefined listening window (e.g., 2 microseconds). In such a scenario, the LIDAR system may obtain information including a distance to ground as a function of yaw angle. The LIDAR system may then use this information to adjust the listening window in subsequent scans.

In some embodiments, a 360 degree scan of the LIDAR system may include a mix of normal/reduced time listening windows and long listening windows on a fine time scale. That is, the LIDAR system may be configured to interleave, alternate, or otherwise mix long listening times with shortened listening windows. Other ways of changing the listening window associated with the emitted light pulses from the LIDAR, particularly in view of the predicted distance from objects in the environment, are contemplated herein.

Additionally or alternatively, the power of each light pulse may be adjusted based on the maximum predicted distance for each combination of yaw angle and beam elevation within a given field of view of the LIDAR. For example, if the sampled data indicates that the maximum predicted distance for a given light pulse is 10 meters, the amount of power provided to the light pulse may be reduced by 80% or more as compared to a light pulse predicted to travel 200 meters. That is, the power of a given light pulse may be related to the maximum reliable detection range. To reduce power usage of the LIDAR system while reliably detecting objects in the environment, the light pulse power may be adjusted based on a maximum predicted distance that the light pulse may travel. In this way, the LIDAR system may more efficiently transmit light pulses into its environment and reduce problems associated with retroreflection and vignetting that may be caused by receiving too many photons from a close range target/object.

Example System

FIG. 1A illustrates a sensing system 10 according to an example embodiment. The sensing system 10 may be a light detection and ranging (LIDAR) system. The sensing system includes a housing 12 that houses an arrangement of various components, such as a transmit block 20, a receive block 30, a shared space 40, and a lens 50. The sensing system 10 includes an arrangement of components configured to provide an emitted light beam 52 from the transmitting block 20, the emitted light beam 52 being collimated by the lens 50 and transmitted as a collimated light beam 54 into the environment of the sensing system 10. Further, the sensing system 10 includes an arrangement of components configured to collect reflected light 56 from one or more objects in the environment of the sensing system 10 through the lens 50 for focusing into focused light 58 towards the receiving block 30. The reflected light 56 includes light from the collimated light beam 54 reflected by one or more objects in the environment of the sensing system 10.

The emitted light beam 52 and the focused light 58 may pass through the shared space 40 also included in the housing 10. In some embodiments, the emitted light beam 52 propagates along a transmit path through the shared space 40, and the focused light 58 propagates along a receive path through the shared space 40.

The sensing system 10 may determine aspects (e.g., location, shape, etc.) of one or more objects in the environment of the sensing system 10 by processing the focused light 58 received by the receiving block 30. For example, sensing system 10 may compare the time at which pulses included in emitted light beam 52 are emitted by transmitting block 20 with the time at which corresponding pulses included in focused light 58 are received by receiving block 30 and determine a distance between one or more objects and sensing system 10 based on the comparison.

The housing 12 included in the sensing system 10 may provide a platform for mounting the various components included in the sensing system 10. The housing 12 may be formed of any material capable of supporting the various components of the sensing system 10 included in the interior space of the housing 12. For example, the housing 12 may be formed from a structural material such as plastic or metal.

In some examples, the housing 12 may include a light shield configured to reduce unintended transmission of ambient light and/or emitted light beams 52 from the transmitting block 20 to the receiving block 30. Light shielding may be provided by forming and/or coating the outer surface of the housing 12 with a material that blocks ambient light from the environment. In addition, the inner surface of the housing 12 may include and/or be coated with the materials described above to optically isolate the transmitting block 20 from the receiving block 30, thereby preventing the receiving block 30 from receiving the emitted light beam 52 before the emitted light beam 52 reaches the lens 50.

In some examples, housing 12 may be configured for electromagnetic shielding to reduce electromagnetic noise (e.g., radio Frequency (RF) noise, etc.) from the surrounding environment of sensor system 10 and/or electromagnetic noise between transmit block 20 and receive block 30. Electromagnetic shielding may improve the quality of the transmitted beam 52 transmitted by the transmit block 20 and reduce noise in the signal received and/or provided by the receive block 30. Electromagnetic shielding may be achieved by forming and/or coating housing 12 with one or more materials such as metal, metallic ink, metallic foam, carbon foam, or any other material configured to suitably absorb or reflect electromagnetic radiation. Metals useful for electromagnetic shielding may include, for example, copper or nickel.

In some examples, the housing 12 may be configured to have a generally cylindrical shape and rotate about an axis of the sensing system 10. For example, the housing 12 may have a generally cylindrical shape with a diameter of about 10 centimeters. In some examples, the axis is substantially vertical. In some examples, by rotating the housing 12 including the various components, a three-dimensional map of a 360 degree view of the environment of the sensing system 10 may be determined without frequently recalibrating the arrangement of the various components of the sensing system 10. Additionally or alternatively, the sensing system 10 may be configured to tilt the axis of rotation of the housing 12 to control the field of view of the sensing system 10.

Although not shown in fig. 1A, the sensing system 10 may optionally include a mounting structure for the housing 12. The mounting structure may include a motor or other means for rotating the housing 12 about the axis of the sensing system 10. Alternatively, the mounting structure may be included in devices and/or systems other than the sensing system 10.

In some examples, various components of the sensing system 10, such as the transmitting block 20, the receiving block 30, and the lens 50, may be removably mounted into predetermined locations of the housing 12 to reduce the burden of calibrating the arrangement of each component and/or sub-components included in each component. Thus, the housing 12 serves as a platform for the various components of the sensing system 10 to provide ease of assembly, maintenance, calibration, and manufacturing of the sensing system 10.

The transmitting block 20 includes a plurality of light sources 22 that may be configured to emit a plurality of emitted light beams 52 via the exit aperture 26. In some examples, each of the plurality of emitted light beams 52 corresponds to one of the plurality of light sources 22. The transmitting block 20 may optionally include a mirror 24 along the transmit path of the emitted light beam 52 between the light source 22 and the exit aperture 26.

Light source 22 may include a laser diode, a Light Emitting Diode (LED), a Vertical Cavity Surface Emitting Laser (VCSEL), an Organic Light Emitting Diode (OLED), a Polymer Light Emitting Diode (PLED), a Light Emitting Polymer (LEP), a Liquid Crystal Display (LCD), a microelectromechanical system (MEMS), or any other device configured to selectively transmit, reflect, and/or emit light to provide a plurality of emitted light beams 52. In some examples, light source 22 may be configured to emit an emitted light beam 52 within a wavelength range that may be detected by detector 32 included in receiving block 30. The wavelength range may be, for example, in the ultraviolet, visible, and/or infrared portions of the electromagnetic spectrum. In some examples, the wavelength range may be a narrow wavelength range, such as provided by a laser. In one example, the wavelength range includes wavelengths of approximately 905 nanometers. Additionally, the light source 22 may be configured to emit the emitted light beam 52 in the form of pulses. In some examples, the plurality of light sources 22 may be disposed on one or more substrates (e.g., printed Circuit Board (PCB), flexible PCB, etc.) and arranged to emit the plurality of light beams 52 toward the exit aperture 26.

In some examples, the plurality of light sources 22 may be configured to emit uncollimated light beams included in the emitted light beams 52. For example, due to the uncollimated light beams emitted by the plurality of light sources 22, the emitted light beams 52 may diverge in one or more directions along the transmission path. In some examples, the vertical and horizontal extent (extent) of the emitted light beam 52 at any location along the transmission path may be based on the degree of divergence of the uncollimated light beams emitted by the plurality of light sources 22.

The exit aperture 26, which is disposed along the delivery path of the emitted light beams 52, may be configured to accommodate the vertical and horizontal extent of the plurality of light beams 52 emitted by the plurality of light sources 22 at the exit aperture 26. Note that for convenience of description, the block diagram shown in fig. 1A is described in connection with functional blocks. However, the functional blocks in the block diagram of fig. 1A may be physically implemented in other locations. For example, although the exit aperture 26 is shown as being included in the sending block 20, the exit aperture 26 may be physically included in both the sending block 20 and the shared space 40. For example, the transmitting block 20 and the shared space 40 may be separated by a wall that includes the outlet aperture 26. In this case, the outlet aperture 26 may correspond to a transparent portion of the wall. In one example, the transparent portion may be a hole or cut-out portion of the wall. In another example, the wall may be formed from a transparent substrate (e.g., glass) coated with an opaque material, and the outlet aperture 26 may be a portion of the substrate that is not coated with an opaque material.

In some examples of the sensing system 10, it may be desirable to minimize the size of the exit aperture 26 while accommodating the vertical and horizontal extent of the plurality of light beams 52. For example, minimizing the size of the exit aperture 26 may improve the light shielding of the light source 22 described above in the function of the housing 12. Additionally or alternatively, the wall separating the transmitting block 20 and the shared space 40 may be arranged along the receiving path of the focused light 58, and thus the exit aperture 26 may be minimized to allow a larger portion of the focused light 58 to reach the wall. For example, the walls may be coated with a reflective material (e.g., reflective surface 42 in shared space 40), and the receiving path may include reflecting focused light 58 toward receiving block 30 by the reflective material. In this case, minimizing the size of the exit aperture 26 may allow a greater portion of the focused light 58 to reflect off of the reflective material coated on the wall.

To minimize the size of the exit aperture 26, in some examples, the divergence of the emitted light beam 52 may be reduced by partially collimating the uncollimated light beam emitted by the light source 22 to minimize the vertical and horizontal extent of the emitted light beam 52, thereby minimizing the size of the exit aperture 26. For example, each of the plurality of light sources 22 may include a cylindrical lens disposed adjacent to the light source. The light source may emit a corresponding uncollimated light beam that diverges more in the first direction than in the second direction. The cylindrical lens may pre-collimate the uncollimated light beam in a first direction to provide a partially collimated light beam to reduce divergence in the first direction. In some examples, the divergence of the partially collimated light beam in the first direction is less than the divergence in the second direction. Similarly, uncollimated light beams from other light sources in the plurality of light sources 22 may have a reduced beam width in the first direction, and thus the emitted light beam 52 may have less divergence due to the partially collimated light beam. In this example, at least one of the vertical and horizontal extent of the exit aperture 26 may be reduced due to the partially collimated light beam 52.

Additionally or alternatively, to minimize the size of the exit aperture 26, in some examples, the light sources 22 may be arranged along a shaped surface defined by the transmitting block 20. In some examples, the shaping surface may be faceted and/or substantially curved. The faceted and/or curved surface may be configured such that the emitted light beam 52 converges towards the exit aperture 26, and thus the vertical and horizontal extent of the emitted light beam 52 at the exit aperture 26 may be reduced due to the arrangement of the light source 22 along the faceted and/or curved surface of the transmitting block 20.

In some examples, the curved surface of the transmitting block 20 may include a curvature along a first direction of divergence of the emitted light beams 52 and a curvature along a second direction of divergence of the emitted light beams 52 such that the plurality of light beams 52 converge along the transmit path toward a central region in front of the plurality of light sources 22.

To facilitate such a curved arrangement of the light sources 22, in some examples, the light sources 22 may be disposed on a flexible substrate (e.g., a flexible PCB) having a curvature along one or more directions. For example, the curved flexible substrate may be curved along a first direction of divergence of the emitted light beam 52 and a second direction of divergence of the emitted light beam 52. Additionally or alternatively, to facilitate such a curved arrangement of the light sources 22, in some examples, the light sources 22 may be disposed on curved edges of one or more vertically oriented Printed Circuit Boards (PCBs) such that the curved edges of the PCBs substantially match the curvature of a first direction (e.g., a vertical plane of the PCBs). In this example, one or more PCBs may be mounted in the transmit block 20 along a horizontal curvature that substantially matches the curvature of the second direction (e.g., the horizontal plane of the one or more PCBs). For example, the transmitting block 20 may include four PCBs, each of which mounts sixteen light sources, so that 64 light sources are provided along the curved surface of the transmitting block 20. In this example, the 64 light sources are arranged in a pattern such that the emitted light beams 52 converge toward the exit aperture 26 of the transmitting block 20.

The transmitting block 20 may optionally include a mirror 24 along the transmit path of the emitted light beam 52 between the light source 22 and the exit aperture 26. By including the mirror 24 in the transmit block 20, the transmit path of the emitted light beam 52 may be folded to provide a smaller size of the transmit block 20 and housing 12 of the sensing system 10 than another transmit block whose transmit path is not folded.

The receiving block 30 includes a plurality of detectors 32 that may be configured to receive the focused light 58 via the entrance aperture 36. In some examples, each of the plurality of detectors 32 is configured and arranged to receive a portion of the focused light 58 corresponding to a beam of light emitted by a respective one of the plurality of light sources 22 and reflected by one or more objects in the environment of the sensing system 10. The receiving block 30 may optionally include a detector 32 in a sealed environment with an inert gas 34.

The detector 32 may include a photodiode, an avalanche photodiode, a Single Photon Avalanche Diode (SPAD), a phototransistor, a silicon photomultiplier (SiPM), a camera, an Active Pixel Sensor (APS), a Charge Coupled Device (CCD), a cryogenic detector, or any other light sensor configured to receive focused light 58 having a wavelength within the wavelength range of the emitted light beam 52.

To facilitate receipt by each of the detectors 32 of portions of the focused light 58 from respective ones of the plurality of light sources 22, the detectors 32 may be disposed on one or more substrates and arranged accordingly. For example, the light source 22 may be disposed along a curved surface of the transmitting block 20. The detector 32 may be disposed along a curved surface of the receiving block 30. In some embodiments, the curved surface of the receiving block 30 may comprise a similar or identical curved surface as the transmitting block 20. Thus, each of the detectors 32 may be configured to receive light originally emitted by a respective light source of the plurality of light sources 22.

To provide a curved surface for the receiving block 30, the detector 32 may be disposed on one or more substrates similar to the light source 22 disposed in the transmitting block 20. For example, the detectors 32 may be disposed on a flexible substrate (e.g., a flexible PCB) and arranged along a curved surface of the flexible substrate to each receive focused light from a respective light source of the light sources 22. In this example, the flexible substrate may be held between two clips having surfaces corresponding to the curved surface shape of the receiving block 30. Thus, in this example, assembly of the receiving block 30 may be simplified by sliding the flexible substrate onto the receiving block 30 and maintaining it at the correct curvature using two clamps.

Focused light 58 passing along the receive path may be received by detector 32 via entrance aperture 36. In some examples, the inlet aperture 36 may include a filter window that passes light having wavelengths within the wavelength range emitted by the plurality of light sources 22 and attenuates light having other wavelengths. In this example, the detector 32 receives focused light 58 that generally includes light having a wavelength within the wavelength range.

In some examples, the plurality of detectors 32 included in the receiving block 30 may include, for example, avalanche photodiodes in a sealed environment filled with inert gas 34. Inert gas 34 may include, for example, nitrogen.

The shared space 40 includes a transmit path of the emitted light beam 52 from the transmit block 20 to the lens 50 and includes a receive path of the focused light 58 from the lens 50 to the receive block 30. In some examples, the transmit path at least partially overlaps the receive path in shared space 40. By including the transmit path and the receive path in the shared space 40, advantages may be provided with respect to the size, cost, and/or complexity of assembly, manufacture, and/or maintenance of the sensing system 10.

While the outlet aperture 26 and the inlet aperture 36 are shown as being part of the transmitting block 20 and the receiving block 30, respectively, it is understood that such apertures may be arranged or placed at other locations. In some embodiments, the functions and structures of the outlet aperture 26 and the inlet aperture 36 may be combined. For example, the shared space 40 may include shared inlet/outlet apertures. It will be appreciated that other ways of disposing the optical components of the system 10 within the housing 12 are possible and contemplated.

In some examples, the shared space 40 may include a reflective surface 42. The reflective surface 42 may be disposed along the receiving path and configured to reflect the focused light 58 toward the entrance aperture 36 and onto the detector 32. The reflective surface 42 may include a prism, mirror, or any other optical element configured to reflect the focused light 58 toward the entrance aperture 36 in the receiving block 30. In some examples, a wall may separate shared space 40 from transmit block 20. In these examples, the wall may include a transparent substrate (e.g., glass) and the reflective surface 42 may include a reflective coating on the wall with an uncoated portion for the exit aperture 26.

In embodiments including reflective surface 42, reflective surface 42 may reduce the size of shared space 40 by folding the receive path similar to mirror 24 in transmitting block 20. Additionally or alternatively, in some examples, the reflective surface 42 may direct the focused light 58 toward the receiving block 30, further providing flexibility in placement of the receiving block 30 in the housing 12. For example, changing the tilt of the reflective surface 42 may cause the focused light 58 to be reflected to various portions of the interior space of the housing 12, so the receiving block 30 may be placed in a corresponding location in the housing 12. Additionally or alternatively, in this example, the sensing system 10 may be calibrated by varying the tilt of the reflective surface 42.

The lens 50 mounted to the housing 12 may have optical power that not only collimates the emitted light beam 52 from the light source 22 in the transmitting block 20, but also focuses reflected light 56 from one or more objects in the environment of the sensing system 10 onto the detector 32 in the receiving block 30. In one example, lens 50 has a focal length of about 120 millimeters. By using the same lens 50 to perform both functions, rather than a transmit lens for collimation and a receive lens for focusing, advantages with respect to size, cost, and/or complexity may be provided. In some examples, collimating the emitted light beam 52 to provide a collimated light beam 54 allows determining a distance that the collimated light beam 54 travels to one or more objects in the environment of the sensing system 10.

Although lens 50 is described herein as being used as a transmitting lens and a receiving lens, it will be appreciated that separate lenses and/or other optical elements are also contemplated as being within the scope of the present disclosure. For example, lens 50 may represent different lenses or lens groups along separate optical transmit and receive paths.

In an example scenario, an emitted light beam 52 from light source 22 passing along a transmit path may be collimated by lens 50 to provide a collimated light beam 54 to the environment of sensing system 10. The collimated light beam 54 may then reflect from one or more objects in the environment of the sensing system 10 and return to the lens 50 as reflected light 56. The lens 50 may then collect and focus the reflected light 56 as focused light 58 onto the detector 32 included in the receiving block 30. In some examples, aspects of one or more objects in the environment of sensing system 10 may be determined by comparing emitted light beam 52 and focused light beam 58. These aspects may include, for example, distance, shape, color, and/or material of one or more objects. Further, in some examples, by rotating the housing 12, a three-dimensional map of the surroundings of the sensing system 10 may be determined.

In some examples where the plurality of light sources 22 are arranged along a curved surface of the transmitting block 20, the lens 50 may be configured to have a focal plane corresponding to the curved surface of the transmitting block 20. For example, the lens 50 may include an aspherical surface on the outside of the housing 12 and an annular surface on the inside of the housing 12 facing the shared space 40. In this example, the shape of the lens 50 allows the lens 50 to both collimate the emitted light beam 52 and focus the reflected light 56. In addition, in this example, the shape of the lens 50 allows the lens 50 to have a focal plane corresponding to the curved surface of the transmitting block 20. In some examples, the focal plane provided by lens 50 substantially matches the curved shape of transmitting block 20. Further, in some examples, the detector 32 may be similarly arranged in the curved shape of the receiving block 30 to receive focused light 58 along a curved focal plane provided by the lens 50. Thus, in some examples, the curved surface of the receiving block 30 may also substantially match the curved focal plane provided by the lens 50.

Fig. 1B illustrates a system 100 according to an example embodiment. The system 100 may describe at least a portion of a LIDAR system. Further, the system 100 may include similar or identical elements to the sensing system 10, as shown and described with reference to fig. 1A. In some embodiments, the system 100 may be incorporated as part of a sensing system of an autonomous or semi-autonomous vehicle (such as the vehicle 300 shown and described with reference to fig. 3 and 4A-4D).

The system 100 includes a plurality of light emitter devices 110, a receiver subsystem 120, and a controller 150. The system 100 further comprises an optical pulse arrangement 160.

In some embodiments, the plurality of light emitter devices 110 may include laser diodes, light emitting diodes, or other types of light emitting devices. In an example embodiment, the plurality of light emitter devices 110 includes InGaAs/GaAs laser diodes configured to emit light at wavelengths of approximately 903 nanometers. In some embodiments, the plurality of light emitting devices 110 includes at least one of a laser diode, a laser bar, or a laser stack. Additionally or alternatively, the plurality of optical transmitter devices 110 may include one or more Master Oscillator Power Amplifier (MOPA) fiber lasers. Such fiber lasers may be configured to provide pulses of light at or about 1550 nanometers and may include a seed laser and a length of active fiber configured to amplify the seed laser to a higher power level. However, other types of light emitting devices, materials, and emission wavelengths are also possible and contemplated.

In some embodiments, the plurality of light emitter devices 110 are configured to emit light into the environment along a plurality of emission vectors to respective target locations in order to provide a desired resolution. In such a scenario, the plurality of light emitter devices 110 are operable to emit light along a plurality of emission vectors such that the emitted light interacts with the external environment of the system 100.

In some embodiments, the system 100 may include at least one substrate having a plurality of angled facets along a front edge. In this case, each angled facet may include a respective die attach location. As an example, each light emitter device may be coupled to a respective die-attach location so as to be operable to emit light along its respective emission vector.

In such embodiments, the at least one substrate may be disposed along one or more vertical planes. In this case, a plurality of emission vectors may be defined with respect to the horizontal plane. Further, as an example, the at least one substrate may be oriented vertically within a housing configured to rotate about a rotational axis, which itself may be substantially vertical. In other words, a plurality of light emitter devices 110 and receiver subsystems 120 may be coupled to the housing. In this scenario, the housing is configured to rotate about a rotational axis.

For example, each light emitter device may be oriented along a common substrate to emit light along a respective emission vector toward a respective target location. It will be appreciated that many different physical and optical techniques may be used to direct light to a given target location. All such physical and optical techniques are contemplated herein.

In some embodiments, the desired resolution may include a target resolution at a given distance from the system 100. For example, the desired resolution may include a vertical resolution of 7.5 centimeters, whichever is closer, at 25 meters from the system 100 and/or between adjacent target locations along the horizontal ground plane. Other desired resolutions along two-dimensional surfaces and in three-dimensional space are also possible and contemplated herein.

In some embodiments, the at least one substrate may be disposed along a vertical plane. In this case, at least two of the plurality of emission vectors may vary with respect to the horizontal plane.

In embodiments in which the plurality of light emitter devices 110 are distributed over a plurality of substrates, each portion of the plurality of light emitter devices 110 may be configured to illuminate the environment at a respective pointing angle relative to the vertical plane. As an example, the plurality of light emitter devices 110 may include at least 64 light emitter devices. However, a greater or lesser number of light emitter devices 110 may be used.

In some embodiments, the plurality of light emitter devices 110 may be configured to provide light pulses having a duration between about 1-10 nanoseconds. Other light pulse durations are also possible.

In some embodiments, system 100 may include an optical element (not shown) that may include a respective lens optically coupled to a respective output facet of a respective light emitter device. The corresponding lenses may include, but are not limited to, fast axis collimating lenses.

In some embodiments, the receiver subsystem 120 may be similar or identical to the receiver block 30, as shown and described with reference to fig. 1A. For example, the receiver subsystem 120 may be configured to provide information indicative of interactions between the emitted light and the external environment. In such a scenario, the receiver subsystem 120 may include a device configured to receive at least a portion of the light emitted from the plurality of light emitter devices 110, so as to correlate the received light pulses with objects in the environment of the system 100.

The receiver subsystem 120 may include a plurality of light detector devices. In such a scenario, the plurality of light detector devices may be configured to detect light having at least one of the following wavelengths: 1550 nm or 780 nm. Other wavelengths are also possible and contemplated herein. In some embodiments, the light detector device may include at least one of: avalanche photodiodes, single Photon Avalanche Detectors (SPADs), or silicon photomultipliers (sipms). In further embodiments, the photodetector device may comprise a plurality of InGaAs photodetectors. Other types of photodetectors are also possible and contemplated.

The controller 150 may include an on-board computer, an external computer, or a mobile computing platform, such as a smart phone, tablet device, personal computer, wearable device, or the like. Additionally or alternatively, the controller 150 may include or be connected to a remotely located computer system, such as a cloud server network. In an example embodiment, the controller 150 may be configured to perform some or all of the method blocks or steps described herein.

The controller 150 may include one or more processors 152 and at least one memory 154. The processor 152 may comprise, for example, an Application Specific Integrated Circuit (ASIC) or a Field Programmable Gate Array (FPGA). Other types of processors, computers, or devices configured to execute software instructions are contemplated herein. Memory 154 may include non-transitory computer-readable media such as, but not limited to, read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM); nonvolatile random access memory (e.g., flash memory), solid State Drive (SSD), hard Disk Drive (HDD), compact Disk (CD), digital Video Disk (DVD), digital tape, read/write (R/W) CD, R/W DVD, and the like.

The one or more processors 152 of the controller 150 may be configured to execute instructions stored in the memory 154 in order to perform the various operations described herein.

Additionally or alternatively, the controller 150 may include circuitry (e.g., synchronous digital circuitry) operable to perform various operations described herein. For example, the circuitry may include a shot table (shot table). Other functions of the circuit (e.g., reading and sequencing) may be performed by synchronous digital logic circuits. In some embodiments, the circuitry and its operation may be specified in Verilog or another hardware description language. In this scenario, the controller 150 need not include a processor.

The operations performed by the controller 150 may include determining a light pulse arrangement for at least one of the plurality of light emitter devices. The light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of the external environment. The light pulse arrangement comprises at least one light pulse parameter and a listening window duration. In some embodiments, the at least one light pulse parameter may comprise at least one of: a desired pulse start time, a desired wavelength, a desired pulse power, or a desired pulse duration. Other types of light pulse parameters may be possible and are contemplated herein.

In some embodiments, determining the arrangement of light pulses may include determining the object and the corresponding object distance. As a non-limiting example, the object may include at least one of: ground surfaces, carriers, obstructions, or shielding elements. In some embodiments, the object is located in the external environment along a respective emission vector of the at least one light emitter device. Further, the operations may include determining a listening window duration based on the respective object distance and the rate of the light pulses.

The operations include causing at least one of the plurality of light emitter devices to emit light pulses according to a light pulse arrangement.

In some embodiments, the operations may additionally or alternatively include receiving information indicative of an interaction between the light pulse and the external environment during the listening window duration. In such a scenario, the operations may include adjusting a three-dimensional map of the external environment based on the received information. Further, in some embodiments, the operations may further include adjusting the light pulse arrangement based on the received information. In some embodiments, the listening window duration is adjustable within a closed interval between 200 nanoseconds and 2 microseconds. However, other listening window durations are also possible and contemplated.

Fig. 2 shows several timing sequences 200, 210, and 220 according to an example embodiment. Timing sequences 200, 210, and 220 may illustrate blocks that may include various modes of operation of the LIDAR device of system 100. In an example embodiment, the timing sequences 200, 210, and 220 may describe different ways of processing the timing between light pulses. In particular, the timing sequences 200, 210, and 220 may describe different scenarios for handling how long the LIDAR system may wait during a predetermined listening window before continuing to transmit the next light pulse.

Block 202 of timing sequence 200 includes causing the light emitter device to at t ₀ The light pulses are transmitted into an environment (e.g., the environment of system 100). Once the light pulse is emitted, the listening window may begin and may remain "open" until t _listening . That is, at t ₀ And t _listening During a listening window in between, a receiver subsystem (e.g., receiver subsystem 120) may be operable to receive reflected light pulses that have interacted with objects in the environment.

As depicted in block 204, in some cases, at a duration t _listening During the listening window of (2), the receiver subsystem may not receive reflected light or receive insufficient reflected light. In such a scenario, the listening window may be "closed" or expired, as shown in block 206. In such a scenario, the system 100 may determine that no object is present along the emission vector of the light pulse within a predetermined range. In some embodiments, the predetermined range may be based on the light pulse that may be capable of being at t _listening The maximum round trip distance of inner travel (e.g., (t) _listening 2) speed of light).

Turning to timing sequence 210, block 202 may again include causing the light emitter device to be at t ₀ A pulse of light is emitted into the environment. In block 212, the light pulse may be at t ₁ Interact with objects in the environment. For example, the light pulse may be reflected from the object and at least a portion of the light from the light pulse may be redirected back to the receiver subsystem. In block 214, the reflected portion of the light may be earlier than t _listening,1 T of (2) ₂ Is received by a receiver subsystem (e.g., receiver subsystem 120). According to timing sequence 210, block 206 may include a listening window expiration (at time t _listening,1 ). Upon expiration of the listening window, block 216 may repeat the timing sequence 210 with subsequent light pulses and listening windows.

Timing sequence 220 may illustrate some of the embodiments described herein. That is, the timing sequence 220 may provide a way to dynamically adjust the duration of the subsequent listening window based on objects in the environment of the system. In this scenario, block 202 includes causing the light emitting device to emit light at t ₀ A pulse of light is emitted into the environment. Furthermore, the light pulse may be at t ₁ Interact with objects in the environment. Further, block 214 may include reflecting light (or at least a portion thereof) at t ₂ Is received by the receiver subsystem. In some embodiments, listening window t _listening,1 May remain open for a predetermined period of time. However, in some cases, the listening window need not remain open for a predetermined time, and the next light pulse may be emitted immediately after receiving the reflected light.

Additionally or alternatively, upon receiving the reflected light, the system (e.g., system 100) may perform block 222. Block 222 may include adjusting a subsequent listening window t _listening,2 . In some embodiments, the subsequent listening window may correspond to an immediately next light pulse and/or another future light pulse that is expected to interact with an object in the environment. In some embodiments, block 222 may be at t _listening,1 Or at a later time.

In an example embodiment, t _listening,2 Can be adjusted to t ₂ . That is, the subsequent listening window may be shortened to match the round trip time of the previous light pulse interacting with the object and returning to the receiver subsystem.

Additionally or alternatively, a subsequent listening period t _listening,2 Can be adjusted to t ₂ +t _buffer . In such an embodiment, t _buffer A "buffer time" may be included to ensure that the subsequent listening window remains open long enough to detect reflected light from the object. In some embodiments, the buffering time may be based on a determined velocity vector of the object. For example, if the object is determined For being moved away from the light source, the buffer time t _buffer Possibly greater than the time of a scene where the distance of the light source to the object is constant. In addition, t _buffer May be a predetermined amount of time corresponding to a maximum velocity vector of the object. For example, the predetermined amount of buffering time may be based on a maximum distance that the object may be at when the subsequent light pulse interacts with the object. It will be appreciated that t _buffer All of which are contemplated herein, based on other considerations as well.

The timing diagram 220 involves setting a predetermined listening period based on objects determined in the system environment. It will be appreciated that such timing diagram 220 may be repeated in a serial and/or parallel manner for each light pulse emitted by each light emitter device and/or system. As such, the light pulse arrangement (e.g., light pulse arrangement 160) may be established and/or adjusted based on objects detected in the environment. That is, the listening period may be reduced or minimized, thereby reducing the time it takes to wait for the listening period to expire even though a reflected light pulse has been detected. By utilizing a dynamic listening period, more light pulses may be transmitted (and more reflected light pulses received), which may provide higher spatial and/or temporal sensing resolution and/or larger field of view sensing for a given amount of time.

Fig. 3 shows a carrier 300 according to an example embodiment. Carrier 300 may include one or more sensor systems 302, 304, 306, 308, and 310. One or more of the sensor systems 302, 304, 306, 308, and 310 may be similar or identical to the sensor system 10. As an example, sensor systems 302, 304, 306, 308, and 310 may include a transmit block 20, as shown and described with reference to fig. 1A. That is, the sensor systems 302, 304, 306, 308, and 310 may include a LIDAR sensor having a plurality of light emitter devices arranged over a range of angles with respect to a given plane (e.g., an x-y plane).

One or more of the sensor systems 302, 304, 306, 308, and 310 may be configured to rotate about an axis perpendicular to a given plane (e.g., the z-axis) in order to illuminate the environment surrounding the carrier 300 with pulses of light. Based on various aspects of the reflected light pulses detected (e.g., elapsed time of flight, polarization, etc.), information about the environment may be determined.

In an example embodiment, the sensor systems 302, 304, 306, 308, and 310 may be configured to provide respective point cloud information related to physical objects within the environment of the vehicle 300. While systems 10 and 100, carrier 300, and sensor systems 302 and 304 are shown as including certain features, it will be appreciated that other types of systems are contemplated within the scope of the present disclosure.

As an example, example embodiments may include a system having a plurality of light emitter devices. The system may include a transmit block of the LIDAR device. For example, the system may be, or may be part of, a LIDAR device of a vehicle (e.g., an automobile, truck, motorcycle, golf cart, aircraft, boat, etc.). Each of the plurality of light emitter devices is configured to emit light pulses along a respective beam elevation angle. As described elsewhere herein, the corresponding beam elevation angle may be based on a reference angle or a reference plane. In some embodiments, the reference plane may be based on an axis of motion of the carrier.

While certain descriptions and illustrations herein describe systems having multiple light emitter devices, LIDAR systems having fewer light emitter devices (e.g., a single light emitter device) are also contemplated herein. For example, the light pulses emitted by the laser diode may be controllably directed around the environment of the system. The emission angle of the light pulses may be adjusted by a scanning device such as, for example, a mechanical scanning mirror and/or a rotating motor. For example, the scanning device may reciprocally rotate about a given axis and/or rotate about a vertical axis. In another embodiment, the light emitter device may emit light pulses towards the rotating prism reflector, which may cause the light pulses to be emitted into the environment based on the angle of the prism reflector angle at which each light pulse interacts. Additionally or alternatively, scanning optics and/or other types of electro-optic mechanical devices may scan the light pulses surrounding the environment.

In some embodiments, a single light emitter device may emit light pulses according to a variable emission arrangement and/or with variable power per emission, as described herein. That is, the transmit power and/or timing of each laser pulse or transmission may be based on the corresponding elevation angle of the transmission. Further, the variable firing arrangement may be based on providing a desired vertical spacing at a given distance from the LIDAR system or from a surface (e.g., front bumper) of a given vehicle supporting the LIDAR system. As an example, when the light pulse from the light emitter device is directed downwards, the power per emission may be reduced due to the shorter maximum distance expected to the target. Conversely, light pulses emitted by the light emitter device at an elevation angle higher than the reference plane may have a relatively higher per-shot power in order to provide a sufficient signal-to-noise ratio to adequately detect pulses traveling longer distances.

Furthermore, the emission schedule may be adjusted to reduce the latency until a subsequent emission of the downward-directed light pulse. That is, the duration of the listening window may not be as long as the duration of the light pulses traveling farther within a given environment, due to the shorter distance traveled.

Fig. 4A shows a side view of a carrier 300 in a sensing scenario 400, according to an example embodiment. In such a scenario, sensor system 302 may be configured to emit pulses of light into the environment of carrier 300 within elevation angle range 410 between maximum elevation angle 412 and minimum elevation angle 414. In some embodiments, the sensor system 302 may include a plurality of light emitter devices arranged in a non-linear elevation distribution. That is, to achieve a desired vertical beam resolution, the plurality of light emitter devices of sensor system 302 may be arranged at beam elevation angles that include non-uniform elevation angle differences between adjacent beams.

As another example, sensor system 304 may be configured to transmit light pulses into the environment of carrier 300 within an elevation range 420, which elevation range 420 may be defined between a maximum elevation 422 and a minimum elevation 424. In some embodiments, the plurality of light emitter devices of the sensor system 304 may illuminate the environment surrounding the carrier 300 with a non-linear elevation distribution. That is, to achieve the desired vertical beam resolution, the plurality of light emitter devices of sensor system 304 may be arranged over a set of beam elevation angles that include non-uniform differences in elevation angles between adjacent beams.

As shown in fig. 4A, the first light pulse path 416 extending from the sensor system 302 may be unobstructed by the object. In such a scenario, the light pulses emitted by the sensor system 302 along the first light pulse path 416 may propagate without interacting with objects in the environment. That is, the light pulses will not be reflected back to the sensor system 302. Determining that the first light pulse path 416 is unobstructed may be based on previous light pulses emitted along the same light pulse path or along substantially similar paths, or based on a two-dimensional or three-dimensional map of the environment surrounding the sensor system 302.

In a scenario where the first light pulse path 416 is determined to be unobstructed or expected to be unobstructed, the predetermined listening period associated with a given light pulse may be set to a maximum listening period duration (e.g., 2 microseconds). Other listening period durations are also possible and contemplated. In some embodiments, setting the listening period to a maximum duration may provide for sensing of the object when the object becomes closer than a predetermined maximum sensing distance.

As shown in fig. 4A, the second light pulse path 426 extending from the sensor system 304 may also be unobstructed by the object. As such, under the methods and systems described herein, the light pulses emitted by the sensor system 304 along the second light pulse path 426 may propagate without interacting with objects in the environment. That is, the light pulses will not be reflected back to the sensor system 304. Determining that the second light pulse path 426 is unobstructed may be based on previous light pulses emitted along the same light pulse path or along substantially similar paths, or based on a two-dimensional or three-dimensional map of the environment surrounding the sensor system 304.

In the event that the second light pulse path 426 is determined to be unobstructed or expected to be unobstructed, the predetermined listening period associated with a given light pulse transmitted along the second light pulse path 426 may be set to a maximum listening period duration (e.g., 2 microseconds). Other listening period durations are also possible and contemplated.

Fig. 4B illustrates a sensing scenario 430 according to an example embodiment. At least some elements of the sense scene 430 may be similar or identical to the sense scene 400. For example, sensor system 302 may be configured to transmit pulses of light into the environment of carrier 300 over an elevation range 410 between a maximum elevation 412 and a minimum elevation 414. Further, sensor system 304 may be configured to transmit light pulses into the environment of carrier 300 over an elevation range 420, which elevation range 420 may be defined between a maximum elevation 422 and a minimum elevation 424.

As shown in fig. 4B, a first light pulse path 432 extending from the sensor system 302 may intersect (interject) with an object such as another carrier 440. That is, the light pulses emitted by the sensor system 302 may interact with the surface 442 of another carrier 440. As shown, surface 442 may include a rear portion of carrier 440. However, it will be appreciated that many other types of objects are possible and contemplated herein. Without limitation, such other types of objects may include road surfaces, obstacles, foliage, buildings, pedestrians, cyclists, other vehicles, and the like.

In addition, the second light pulse path 434 extending from the sensor system 304 may also intersect the object (e.g., at the rear bumper portion of another carrier 440).

In sensing scene 430, at least some of the emitted light pulses may be reflected by surface 442 as reflected light. The round trip time may be provided when the reflected light is received by the sensor system 302 or 304. Based at least on the determined round trip time, the relative distances between the sensor systems 302 and 304 and the other carriers 440 may be estimated or otherwise determined.

As such, under the methods and systems described herein, the light pulses emitted (by the sensor system 302 along the first light pulse path 432 or by the sensor system 304 along the second light pulse path 434) may have an associated listening period that may be based on an estimated or predicted distance to the object. As an example, the listening period duration may be set equal to the amount of time that is expected to be round trip time to surface 442 and back (e.g., 200 nanoseconds). Other listening period durations are also possible and contemplated.

As described elsewhere herein, the estimated or predicted distance to the object may be based on a LIDAR point cloud, or a three-dimensional map (e.g., depth map) or a two-dimensional map. Furthermore, the associated listening period set for the light pulses emitted towards the intended object may be based on the intended distance to the target or the intended distance to the target plus a buffer time in order to account for possible relative movement between the sensor systems 302 and 304 and the carrier.

Fig. 4C and 4D illustrate a further sensing scenario comprising a carrier 300. Fig. 4C shows a rear view of carrier 300 in a sensing scene 450. As shown in the sensing scenario 450, the sensor systems 302, 308, and 310 may be unobstructed except for the ground surface. For example, sensor system 302 may be configured to detect an object over an elevation range 460 having a maximum elevation 462 and a minimum elevation 464. Similarly, sensor systems 308 and 310 may provide respective ranges of elevation angles 470a and 470b, which may be defined by respective maximum elevation angles 472a and 472b and respective minimum elevation angles 474a and 474 b.

The sensing scene 450 may include a respective light pulse arrangement (e.g., light pulse arrangement 160) for each of the sensor systems 302, 308, and 310. Furthermore, each of the light pulse arrangements may comprise a predetermined listening period based on a maximum sensed distance or an expected ground position.

Fig. 4D illustrates a sensing scenario 480 according to an example embodiment. The sensing scene 480 may include a vehicle 440, which may be in an adjacent lane of a multi-lane roadway. In this way, light pulses emitted from sensor system 302 at some elevation angle (such as elevation angle 484) may interact with surface 482 of carrier 440. Further, light pulses emitted from sensor system 308 at various elevation angles (such as elevation angle 486) may interact with surface 484. In such an embodiment, the round trip time of the reflected light pulse would be less than the round trip time of the light pulse reflected from the ground surface. In this way, in a scene such as the sensing scene 480 where the presence or expected presence of an object surface (e.g., surface 482) is determined or expected, the light pulse arrangement may be adjusted based on the shortened listening period of the corresponding reflected light pulses. It will be appreciated that the sense scene 480 may include many other different types of objects and the locations of these objects.

Example embodiments may include adjusting various aspects of the emitted light pulses and/or listening window durations based on changing environments around the vehicle as the vehicle moves around the world. In particular, aspects of the emitted light pulses and their associated listening window durations may vary based on, but not limited to, the following: a rough road (e.g., traveling uphill or downhill, traveling around a curve, etc.), an object on or adjacent to a road (e.g., a pedestrian, other vehicle, building, etc.), or other statically or dynamically changing environmental conditions or circumstances.

Fig. 4E illustrates a sensing scenario 490 according to an example embodiment. Carrier 300 may be in contact with uphill road surface 491. In such a scenario, the object that we may be interested in sensing may include other vehicles (e.g., oncoming vehicles on a mountain) that are in contact with the same road surface 491. Such objects and/or other vehicles that may interfere with the path of travel of the traveling vehicle may be between 0 and 4 meters above the road surface 491. As such, while the sensor 302 may be operable to sense objects between the minimum beam elevation 492 to the maximum beam elevation 493, in some embodiments, data obtained between the minimum beam elevation 492 and the dynamically changing "glancing" beam elevation 494 may be designated as more important or of higher priority for detecting other vehicles and objects along the relief road surface 491. The "glancing" beam elevation angle 494 may be dynamically defined as a scan angle corresponding to a particular location 488, which particular location 488 may be at a predetermined height above the roadway and a predetermined distance from the carrier 300. In an example embodiment, the particular location 488 may be approximately 4 meters above the ground at approximately 60 meters from the carrier 300.

Thus, in some embodiments and under some conditions, the systems and methods described herein need not always scan the entire range of possible beam elevation angles (e.g., angles between the entire angular range between the minimum beam elevation angle 492 and the maximum beam elevation angle 493). Alternatively, the beam scan range may vary based on a dynamically changing yaw-dependent profile of the road and/or other portions of the environment surrounding the vehicle 300.

Referring to fig. 4E, in some embodiments, there is no need to scan the beam elevation angle between the "grazing ground" beam elevation angle 494 and the maximum beam elevation angle 493 at all. That is, for a given yaw angle, there is no need to transmit pulses of light into a range of elevation angles that are predicted to not include objects that might interfere with the advancement of the carrier 300. Additionally or alternatively, light pulses may be emitted into those angular ranges, but the corresponding listening window may be shortened or completely eliminated.

In some embodiments, the listening window duration may be adjusted within a range of predetermined listening window durations. In this scenario, the range of the predetermined listening window duration may include a maximum listening window duration that may correspond to a maximum detection range and a minimum listening window duration that may correspond to a minimum detection range. As an example, the maximum detection range may be about 200 meters or more. In some embodiments, the minimum detection range may be about 5 meters or less. Accordingly, to detect round trip light pulses, the maximum and minimum listening window durations may be 1.3 microseconds and 33 nanoseconds, respectively. Other maximum and minimum listening window durations are also possible and contemplated.

Further, for light pulses emitted into the angle between the minimum beam elevation angle 492 and the "glancing ground" beam elevation angle 494, the corresponding listening window may be lengthened (or maximized) in an attempt to increase the likelihood that an object on or near the ground will be detected.

In some embodiments, the systems and methods described herein may adjust aspects of the listening window and/or light pulse emissions based on a contour line of a continuous line extending around the carrier (e.g., through 360 degrees or more yaw angles) and may be defined to be located a predetermined distance (e.g., 60, 100, or 200 meters away) from the carrier 300 and/or a predetermined height above the ground surface. Such contours may be dynamically adjusted as the carrier 300 moves around its environment. The contour lines may be determined based on a topography map or current or previous point cloud information obtained by the vehicle 300 and/or other vehicles. In some embodiments, the contour lines may pass through the various points depicted in FIGS. 4A-4F. For example, the contour lines may pass through specific locations 488 and 489.

In other words, consider a scenario in which the contour line represents a predetermined height of one meter from the ground at 60 meters from the carrier 300. When the vehicle 300 is on a flat terrain without objects at one meter from the ground, the contour line may be represented by a two-dimensional circle with a radius of 60 meters centered on the vehicle. However, when the vehicle 300 encounters hilly terrain and/or objects at one meter from the ground, the contour lines may include three-dimensional circles, ovals, or irregular shapes based on the terrain features and/or object data. In some embodiments, the listening window duration may be adjusted based on the shape of the contour.

Fig. 4F illustrates a sensing scenario 495 according to an example embodiment. Carrier 300 may be in contact with downhill path surface 499. As described above with reference to fig. 4E, some beam angles of sensor 302 may be "prioritized over" other beam angles. For example, the "glancing" beam elevation angle 498 may be dynamically changed based on a particular location 489 (which may be defined for each yaw angle), the particular location 489 corresponding to a predetermined distance from the carrier 300 and a predetermined height with respect to the ground surface. The range of beam angle elevations between the "ground" beam elevation 498 and the minimum beam elevation 496 may be prioritized over other beam elevations (e.g., beam elevations between the "ground" beam elevation 498 and the maximum beam elevation 497).

As described above, in some embodiments, the light pulses need not be emitted into a beam elevation angle that is higher than the "grazing" beam elevation angle 498. Additionally or alternatively, the listening window duration for light pulses transmitted into such elevation angle range may be reduced or eliminated entirely. Other differences between the transmission and reception of light pulses to a yaw-dependent beam angle range are possible based on topography, point cloud information, or other knowledge about objects and/or ground surfaces within the environment of the carrier 300. In some embodiments, the point cloud information may be collected by a vehicle utilizing the LIDAR system (from a previous scan in driving early and/or from a previous driving scan of a vehicle along the same route) or another vehicle utilizing the LIDAR system. The other carrier may be part of a common carrier team or associated with a different team.

Fig. 5 illustrates a system 500 having a plurality of light emitter devices 516a-516j according to an example embodiment. The system 500 may include a portion of a LIDAR transmit block that includes a substrate 510. The substrate 510 may be formed of a printed circuit board material. In some embodiments, the substrate 510 may be formed by laser cutting and precision drilling operations. Substrate 510 may include a wirebondable finish such as electroless nickel palladium Immersion Gold (ENEPIG). The at least one substrate 510 may include a plurality of angled facets 512a-512j along a front edge and a die attach location (not shown) corresponding to each angled facet 512a-512 j. In this scenario, the plurality of angled facets 512a-512j provide a corresponding plurality of elevation angles. In an example embodiment, a set of angle differences between adjacent elevation angles may include at least two different angle differences. That is, the elevation angles do not include a uniform angle difference, but the angle differences may differ from each other based on, for example, the respective elevation angles and whether the elevation angles are oriented below or above the horizontal plane. In general, elevation angles oriented below horizontal may be more widely spaced, at least because photons are less likely to travel as far as photons at higher elevation angles.

A plurality of light emitter devices 516a-516j may be attached to respective die attach locations. In this way, each light emitter device may be oriented such that the light pulses are emitted along different elevation angles. Further, each respective one of the plurality of light emitter devices 516a-516j may be attached to a respective plurality of pulse generator circuits 520a-520j. In some example embodiments, the respective pulse generator circuits may cause the light emitter devices 516a-516j to emit light pulses as described herein. Further, the plurality of pulse generator circuits 520a-520j may be controlled based at least in part on the light pulse arrangement described herein (e.g., light pulse arrangement 160).

The light pulse arrangement may be dynamically adjusted based on the object being sensed or predicted to be along a given corresponding elevation angle (or emission vector). In some embodiments, if a given light pulse is predicted or interacts with an object in the environment, a corresponding listening window may be set or adjusted based at least in part on a known or predicted distance to the object.

In addition, other optical elements may be included in system 500. For example, a respective plurality of lenses 518a-518j may be optically coupled to a respective plurality of light emitter devices 516a-516j. In addition, other elements may be included in the system 500, such as alignment features 524, communication interfaces 522, sockets 521, and other electronic components 523a and 523b.

Example method

Fig. 6 illustrates a method 600 according to an example embodiment. It will be appreciated that method 600 may include fewer or more steps or blocks than are explicitly shown or otherwise disclosed herein. Furthermore, the respective steps or blocks of method 600 may be performed in any order, and each step or block may be performed one or more times. In some embodiments, some or all of the blocks or steps of method 600 may be performed by controller 150 as shown and described with respect to fig. 1B. Further, the method 600 may be at least partially illustrated by the timing diagram 220 as described with respect to fig. 2. Furthermore, the method 600 may be performed at least in part by the carrier 300 as shown and described with respect to fig. 3. Method 600 may be performed in a scenario similar or identical to scenario 400, 430, 450, and 480 as shown and described with respect to fig. 4A-4D.

Block 602 includes determining a light pulse arrangement for at least one light emitter device of a plurality of light emitter devices. In such a scenario, the plurality of light emitter devices are operable to emit light along a plurality of emission vectors. The light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of the external environment. The light pulse arrangement comprises at least one light pulse parameter and a listening window duration.

In some embodiments, determining the light pulse arrangement may include determining an object and a corresponding object distance. In such a scenario, the object is located in the external environment along a respective emission vector of the at least one light emitter device. The method 600 may further include determining a listening window duration based on the corresponding object distance and the rate of the light pulses.

In some embodiments, the object may include at least one of: ground surfaces, carriers, obstructions, or shielding elements.

Further, in some cases, determining the light pulse arrangement may include adjusting the listening window duration within a closed interval between about 200 nanoseconds and about 2 microseconds. Other listening window durations are also possible and contemplated.

Block 604 includes causing at least one light emitter device of the plurality of light emitter devices to emit light pulses according to a light pulse arrangement. The light pulses interact with the external environment.

In some embodiments, method 600 includes rotating the housing about a rotational axis. In this scenario, a plurality of light emitter devices are coupled to the housing. As described elsewhere herein, the light emitter device may be rotated about an axis of rotation similar to the sensor 302 as shown and described with respect to fig. 3.

Additionally, the method 600 may include, during the listening window duration, receiving information indicative of an interaction between the light pulse and the external environment. In such a scenario, the method 600 may further include adjusting the three-dimensional map of the external environment based on the received information. Additionally or alternatively, the method 600 may include adjusting the light pulse arrangement based on the received information.

The particular arrangements shown in the drawings should not be construed as limiting. It should be understood that other embodiments may include more or less of each of the elements shown in a given figure. Furthermore, some of the illustrated elements may be combined or omitted. Furthermore, the illustrative embodiments may include elements not shown in the drawings.

The steps or blocks representing processing of information may correspond to circuitry which may be configured to perform specific logical functions of the methods or techniques described herein. Alternatively or additionally, steps or blocks representing processing of information may correspond to modules, segments, physical computers (e.g., field Programmable Gate Arrays (FPGAs) or Application Specific Integrated Circuits (ASICs)), or portions of program code (including related data). The program code may include one or more instructions executable by a processor for performing specific logical functions or acts in a method or technique. The program code and/or related data may be stored on any type of computer-readable medium, such as a storage device including a diskette, hard drive, or other storage medium.

Computer-readable media may also include non-transitory computer-readable media such as computer-readable media that store data for a short period of time, like register memory, processor cache, and Random Access Memory (RAM). The computer readable medium may also include a non-transitory computer readable medium that stores program code and/or data for a longer period of time. Thus, the computer readable medium may comprise a secondary or permanent long term storage device, such as, for example, a Read Only Memory (ROM), an optical or magnetic disk, a compact disk read only memory (CD-ROM). The computer readable medium may also be any other volatile or non-volatile memory system. For example, a computer-readable medium may be considered a computer-readable storage medium, or a tangible storage device.

While various examples and embodiments have been disclosed, other examples and embodiments will be apparent to those skilled in the art. The various examples and embodiments disclosed are for illustrative purposes, not for limitation, the true scope being indicated by the following claims.

Claims

1. A system (100) comprising:

a plurality of light emitter devices (110), wherein the plurality of light emitter devices are operable to emit light along a plurality of emission vectors such that the emitted light interacts with an external environment of the system;

A receiver subsystem (120) configured to provide information indicative of an interaction between the emitted light and an external environment; and

a controller (150) operable to perform operations comprising:

determining a light pulse arrangement for at least one light emitter device of the plurality of light emitter devices, wherein the light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of an external environment, wherein the light pulse arrangement comprises at least one light pulse parameter and a listening window duration; and

such that at least one of the plurality of light emitter devices emits light pulses according to the light pulse arrangement.

2. The system of claim 1, wherein the plurality of light emitter devices comprises at least one of a laser diode, a laser bar, or a laser stack.

3. The system of claim 1, wherein the receiver subsystem comprises a plurality of light detector devices, wherein the light detector devices comprise at least one of: avalanche photodiodes, single Photon Avalanche Detectors (SPADs), or silicon photomultipliers (sipms).

4. The system of claim 3, wherein the plurality of light detector devices are configured to detect light of a wavelength comprising at least one of: 1550nm or 780nm.

5. The system of claim 1, further comprising:

at least one substrate disposed along a vertical plane, wherein each light emitter device is coupled to the substrate so as to be operable to emit light along its respective emission vector, wherein at least two of the plurality of emission vectors vary relative to the horizontal plane.

6. The system of claim 1, further comprising:

a housing (12), wherein the plurality of light emitter devices and the receiver subsystem are coupled to the housing, wherein the housing is configured to rotate about a rotational axis.

7. The system of claim 1, wherein determining the light pulse arrangement comprises:

determining an object and a corresponding object distance, wherein the object is located in an external environment along a respective emission vector of the at least one light emitter device; and

the listening window duration is determined based on the corresponding object distance and the rate of the light pulses.

8. The system of claim 7, wherein the object comprises at least one of a ground surface, a vehicle, an obstacle, or a shading element.

9. The system of claim 1, wherein the at least one light pulse parameter comprises at least one of: a desired pulse start time, a desired wavelength, a desired pulse power, or a desired pulse duration.

10. The system of claim 1, wherein the operations further comprise:

receiving information indicating an interaction between the light pulse and the external environment during the listening window duration; and

based on the received information, the light pulse arrangement is adjusted.

11. The system of claim 10, wherein adjusting the light pulse arrangement comprises:

based on the received information, a three-dimensional map of the external environment is adjusted.

12. The system of claim 1, wherein the listening window duration is adjustable within a closed interval between 100 nanoseconds and 2 microseconds.

13. A method, comprising:

determining a light pulse arrangement for at least one of a plurality of light emitter devices (110), wherein the plurality of light emitter devices are operable to emit light along a plurality of emission vectors, wherein the light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of an external environment, wherein the light pulse arrangement comprises at least one light pulse parameter and a listening window duration; and

such that the at least one light emitter device of the plurality of light emitter devices emits light pulses according to a light pulse arrangement, wherein the light pulses interact with an external environment.

14. The method of claim 13, further comprising:

such that the housing rotates about a rotational axis, wherein the plurality of light emitter devices are coupled to the housing.

15. The method of claim 13, wherein determining the light pulse arrangement comprises:

determining an object and a respective object distance, wherein the object is located in an external environment along a respective emission vector of the at least one light emitter device; and

16. The method of claim 15, wherein the object comprises at least one of a ground surface, a vehicle, an obstacle, or a shading element.

17. The method of claim 13, further comprising:

18. The method of claim 17, further comprising:

based on the received information, the light pulse arrangement is adjusted.

19. The method of claim 13, wherein determining the light pulse arrangement comprises adjusting a listening window duration within a closed interval between 100 nanoseconds and 2 microseconds.

20. A system, comprising:

a plurality of light emitter devices, wherein the plurality of light emitter devices are operable to emit light along a plurality of emission vectors such that the emitted light interacts with an external environment of the system;

a receiver subsystem configured to provide information indicative of an interaction between the emitted light and an external environment; and

a controller operable to perform operations comprising:

determining a light pulse arrangement for at least one of the plurality of light emitter devices, wherein the light pulse arrangement is based on a respective emission vector of the at least one light emitter device and a three-dimensional map of an external environment, wherein the determined light pulse arrangement comprises at least one light pulse parameter and a listening window duration; and

causing at least one of the plurality of light emitter devices to emit a first light pulse according to the determined light pulse arrangement and a second light pulse according to a default light pulse arrangement.